Monitoring respiratory events is of clinical importance in the early detection of potentially fatal conditions. Current technologies involve contact sensors the individual must wear constantly. Such a requirement can lead to patient discomfort, dependency, loss of dignity, and further may fail due to a variety of reasons including refusal to wear the monitoring device. Elderly patients and neo-natal infants are even more likely to suffer from the adverse effects of continued monitoring. Unobtrusive, non-contact, imaging based methods are increasingly desirable for respiratory function monitoring.
Prior methods capture video images of a region of interest of a subject and process the video to obtain physiological measurements relative to cardiac and respiratory function. These systems track a photoplethysmographic signal reflected off a region of exposed skin. The reflected signals are processed to identify and isolate components relating to a pulsating blood volume. If a region of exposed skin is absent then the video camera cannot register these signals. Although recordings of 2D videos of a non-skin region contain motion related information, previous attempts to isolate respiratory signals purely based on motion have not been successful. The present invention is directed to overcoming these drawbacks.
Accordingly, what is needed in this art are sophisticated systems and methods for estimating a respiration rate for a subject of interest captured in a video containing a view of that subject's thoracic region.